Channel Estimation for Self-Interference Cancellation in Full-Duplex Wireless Systems

Abstract

In this paper, analog cancellation with a self-interference channel estimation scheme is proposed for full-duplex wireless systems. The aim of the proposed scheme is to cancel the self-interference signal at a full-duplex node for orthogonal frequency division multiplexing systems in a multipath self-interference channel with small delay spread. In the proposed scheme, the analog self-interference signal is emulated on the basis of baseband channel estimation. Assuming that a multipath self-interference channel has small delay spread, the proposed channel estimator provides effective channel gain and effective delay estimates of the self-interference channel on the basis of the maximum-likelihood criterion. Numerical results indicate that the self-interference suppression performance of the proposed analog cancellation scheme is better than the performance of the conventional schemes in a small delay spread multipath environment.